Try with one card, then swap the two cards over, and try both cards in both slots just in case its a slot problem (a very uncomfortable tee-shirt...)

At 8 years old your PSU will at the very least need a good clean out as it will have accumulated a vast amount of dust on everything which will hinder it working to its fullest.

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Bob Smith
Member of Seti PIPPS (Pluto is a Planet Protest Society)
Somewhere in the (un)known Universe?

Try with one card, then swap the two cards over, and try both cards in both slots just in case its a slot problem (a very uncomfortable tee-shirt...)

At 8 years old your PSU will at the very least need a good clean out as it will have accumulated a vast amount of dust on everything which will hinder it working to its fullest.

I just removed one card. We'll see if any invalids come from this point forward.

Thanks everyone for the suggestions.

Well, in another thread, everyone agreed there was something seriously wrong with this scenario;
http://setiathome.berkeley.edu/workunit.php?wuid=1407178585

   Task	         Computer 	              Sent     	            Time reported                            Status 	                Run time      CPU time           Credit 	              Application
3343737582 	6563619 	20 Jan 2014, 4:12:18 UTC 	20 Jan 2014, 15:05:36 UTC 	Completed, validation inconclusive 	14,025.99 	13,976.88 	pending 	SETI@home v7 v7.00
3343737583 	7063373 	20 Jan 2014, 4:12:19 UTC 	20 Jan 2014, 14:55:10 UTC 	Completed, marked as invalid 	         1,575.32 	  230.87     	0.00   	     SETI@home v7 Anonymous platform (NVIDIA GPU)
3344800274 	--- 	--- 	--- 	Unsent

Instant Invalid...I hate it when that happens.

Well, in another thread, everyone agreed there was something seriously wrong with this scenario;
http://setiathome.berkeley.edu/workunit.php?wuid=1407178585

   Task	         Computer 	              Sent     	            Time reported                            Status 	                Run time      CPU time           Credit 	              Application
3343737582 	6563619 	20 Jan 2014, 4:12:18 UTC 	20 Jan 2014, 15:05:36 UTC 	Completed, validation inconclusive 	14,025.99 	13,976.88 	pending 	SETI@home v7 v7.00
3343737583 	7063373 	20 Jan 2014, 4:12:19 UTC 	20 Jan 2014, 14:55:10 UTC 	Completed, marked as invalid 	         1,575.32 	  230.87     	0.00   	     SETI@home v7 Anonymous platform (NVIDIA GPU)
3344800274 	--- 	--- 	--- 	Unsent

Instant Invalid...I hate it when that happens.

]

Very interesting... The other thread is the discussion you've had going for a while recently? I was reading over that seeing if any of it applied to me, but a lot of it was over my head.

Thanks for pointing this out. I won't take that work unit seriously then in my experiments.

The specifics of your task doesn't fit in with the other thread. However, your task doesn't appear to warrant an Instant Invalid. Reducing the Memory Clock did move your results much closer to the wingpeople, but still not there exactly.

BTW, I've found that an old Power Supply + Leaf Blower = big cloud of dust.

The specifics of your task doesn't fit in with the other thread. However, your task doesn't appear to warrant an Instant Invalid. Reducing the Memory Clock did move your results much closer to the wingpeople, but still not there exactly.

BTW, I've found that an old Power Supply + Leaf Blower = big cloud of dust.

Ha, I took my can of canned air to the power supply with minimal results unfortunately. Certainly not as powerful as a leaf blower.

Since taking one of my cards out, I have gotten 4 inconclusives. I know, they aren't invalid (yet), but that isn't a good sign :(

Hello everyone, I have an update for those interested. A few days have gone by with only one 650ti crunching. At first, I thought that it was improved. I was crunching at the recommended GPU and memory clock levels thanks to everyone in this thread. (925gpu and 5000 memory).

After a few days, my single 650ti is still producing more valid work than my old 2 cards combined, but the inconclusives and invalids are about on the same level as they were before. A few here and there, maybe less than 1% of the WUs being invalid and 5-8% ending up in the inconclusive pile where they may or may not end up being okay. I haven't switched PCI slots or anything like that, because when I had both cards running, the same result occured but just twice as fast.

I am not opposed to purchasing a new power supply if some folks here still believe that that would help me. Other than that, I am a bit out of ideas!

If your PSU have more than 1 12V rail, try to conect the GPU to a diferent rail than the rest of the MB/HDD, etc. That could give you a path to follow.

If that your case I still belive the problem could be originated from a random spike on the power used by the GPU, something not easely see in humans speeds.

Old PSUs (before the GPU era) are not swited to drive high current spikes needed by the moderns GPU´s.

But test before you going to buy a new PSU, the problem could be originated from other source.

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If your PSU have more than 1 12V rail, try to conect the GPU to a diferent rail than the rest of the MB/HDD, etc. That could give you a path to follow.

If that your case I still belive the problem could be originated from a random spike on the power used by the GPU, something not easely see in humans speeds.

Old PSUs (before the GPU era) are not swited to drive high current spikes needed by the moderns GPU´s.

But test before you going to buy a new PSU, the problem could be originated from other source.

Thanks for responding, Juan.

I am not quite familiar with the terminology of PSUs. There are a whole bunch of wrapped cords coming out of the power supply. It appears to be 2 separate cords for the GPUs, and another cord coming out that appears to plug into the motherboard.

I believe that you are suggesting switching cords for the GPU? Neither GPU cord seems to be sharing anything with the cord that switches into the motherboard, so I am not sure that I can accomplish what you suggest.

mherr.. just a quick question, but do you have this computer plugged into an UPS or the plug in the wall?

mherr.. just a quick question, but do you have this computer plugged into an UPS or the plug in the wall?

Hey Zalster! It is plugged into a strip outlet, and that strip outlet is plugged into the wall.

I don't know about the rest, but I have all of my computers plugged into Uninterrupted Power Sources. I can't tell you how many times a day I hear it kick over to give extra power to the computer when the voltage drops. Since we seem to be focusing on power and/or voltage, I wonder if dips in power might be causing some of these issues. Surge protectors are good but UPS are better protection for your computers. You would need one that is rated for 750 Watts so it meets the demands of your computer. Just my 2 cents.

With your current PSU mherr I'd bet that 1 12v rail for each GPU, 1 for Mobo and the other for fans and drives, but at 8yrs old they would almost certainly be suffering electrical sag.

I'm a great fan of Corsairs TX range of PSU's (the non-modular type) with their high Amp single 12V rail (I use the TX850's in both my rigs) though a TX750 or even a TX650 would suit your current setup with both cards installed.

The reason I'm against multiple rails is because you have to balance the hardware to suit the PSU instead of letting the hardware balance itself.

The reason I'm not a fan of modular PSU's is that each cable connector on the back of the PSU adds another failure point to the PSU (I know as I've replaced enough of them with burnt out connectors on the back of the PSU) even though they do make a tidier look to the case internally.

Cheers.

If you don´t know how it´s better not touch, PSU are highly temperamental, and have the tendency to short circuit something clearely not good.

You should try another aproach, do you have a way to get another, with more capacity, PSU to test for some time?

What you need is to be sure the problem source, is the PSU? the GPU itself? the configuration? the windows? etc. Too many possible sources. In technical language, "isolate" the source of the problem. Only after that you cound find the fix.

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If you don´t know how it´s better not touch, PSU are highly temperamental, and have the tendency to short circuit something clearely not good.

You should try another aproach, do you have a way to get another, with more capacity, PSU to test for some time?

What you need is to be sure the problem source, is the PSU? the GPU itself? the configuration? the windows? etc. Too many possible sources. In technical language, "isolate" the source of the problem. Only after that you cound find the fix.

I wouldn't say that they're temperamental if you pick the right 1 to suit your setup, but picking the wrong 1 will lead to problems and usually very quickly.

Cheers.

That´s why i said... if you don´t know... not touch... :)

A wrong PSU is a major source of a lot of wierd things and a possible source of smoke in your farm. :(

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I wasn't meaning to diss on you Juan (that's an apology if you took me the wrong way), I was just trying to point out that there are "horses for courses" and I don't believe any other variables should be involved here other than the PSU (I could be wrong but really I doubt it).

10yrs (and more ago) I use to carry a few spare PSU's, now people ask me why I don't carry any at all now, but today there are so many factors involved that I just can't do that these days (PC parts from my suppliers take 4-5 days to get here from either Brisbane or Sydney).

mherr's setup worked fine before his GPU upgrade and that very old PSU that he has now I believe was very optimistically rated to start with when new (I believe that 16amp per 12V rail would likely be closer to the truth than the rated 18amps when new, but now after 8yrs it maybe very lucky to achieve 12-14amps per rail).

Cheers.

Thanks everyone for your continued input.

I will probably end up getting a new PSU eventually. Even if it doesn't fix the problem, it will be an inexpensive introduction to another piece of the computer I should be more familiar with.

I haven't done any research yet, but I wonder how the single rail will work. I'm not sure I've ever seen one! And I wonder if most PSU's are of similar size? I wouldn't want to order one just to find out that it doesn't fit inside my case.

Thanks everyone for your continued input.

I will probably end up getting a new PSU eventually. Even if it doesn't fix the problem, it will be an inexpensive introduction to another piece of the computer I should be more familiar with.

I haven't done any research yet, but I wonder how the single rail will work. I'm not sure I've ever seen one! And I wonder if most PSU's are of similar size? I wouldn't want to order one just to find out that it doesn't fit inside my case.

12V Multi-rail PSU's only came out about 8-9yrs ago and unless they are of the oversized variety they're only split electrically, not physically, but they all follow the ATX specifications except in their length. If your Dell had been older 20 pin then I'd say to check its motherboard connector wiring as they use to wire the plug differently to standard PSU's.

Just to be sure the motherboard plug should be wired this way, http://cdn.overclock.net/d/da/da87333a_ATX24-1.jpeg.

Cheers.